Pay-per-call API platform on Base with USDC payments via x402 — $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad collection of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no commitments required. The x402 payment protocol handles authentication: callers include an X-PAYMENT header with a signed USDC payment, and the server fulfills the request upon verification.
The specific endpoint at `/api/v1/transactions/200` is listed as "Premium API Access." Based on the x402 challenge, it accepts POST requests and charges a maximum of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The response MIME type is application/json. No detailed input/output schema is documented beyond the basic HTTP POST method.
The platform advertises additional endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure (geocoding, validation, conversion, generation). All are priced identically at $0.02 per call. Documentation pages (/docs, /pricing, /api, /README) appear to require wallet connection and contain no publicly crawlable content.
Capabilities
Use cases
- —Agents needing on-demand API access without pre-registration or API keys
- —Programmatic access to analytics, AI inference, or financial data with per-call USDC payments
- —Web3 applications that want to consume utility APIs settled on Base
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —AI agents with USDC wallets on Base looking for cheap per-call endpoints
- —Prototyping and low-volume usage where $0.02/request is cost-effective
Not for
- —High-volume production workloads where per-call crypto payments add latency
- —Users without a Base-compatible USDC wallet
- —Anyone needing detailed API documentation — docs pages are currently behind a wallet-connect gate
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/200 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-signed-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no documented request/response schema, no examples, and all documentation pages are gated behind wallet connection. The purpose of the specific /api/v1/transactions/200 endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —No public documentation available — /docs, /pricing, /api, and /README all return only a 'Connect wallet' prompt with no content.
- —The specific purpose and expected input/output of /api/v1/transactions/200 is undocumented.
- —No OpenAPI schema or request/response examples are available.
- —The broad range of advertised endpoints (AI, finance, geo, etc.) cannot be verified for actual functionality from the crawl data.
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/transactions/200 specifies maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base.https://lowpaymentfee.com/api/v1/transactions/200
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com